The present invention relates to a quick connector, for example, to be adapted in assembly in a gasoline fuel piping of an automobile.
In a fluid piping structure, for example, a gasoline fuel piping structure where a tube is joined to a pipe, a connector is used for joining the tube to the pipe. In such piping system, for example, as shown in U.S. Pat. No. 6,129,393, a pipe includes an inserting end portion on one axial side thereof wherein an annular engagement projection is formed on and around an outer peripheral surface. Then, the inserting end portion of the pipe is inserted and fitted in the connector so that the annular engagement projection snap-engages with the connector to provide locking relation between the pipe and the connector, thereby connection between the pipe and the connector is completed. A quick connector adapted in this manner comprises a tubular connector housing and a retainer. The tubular connector housing is provided with a tube connecting portion on one axial side and a retainer holding portion on an opposite axial side thereof. The retainer has a main body formed with a pipe engagement portion to be snap-engaged with an annular engagement projection of the pipe and is fitted in the retainer holding portion. The pipe is inserted in this retainer so that the annular engagement projection of the inserting end portion snap-engages with the pipe engagement portion of the retainer and is thereby fitted in and connected with the connector.
The man body of the retainer is shaped annular or generally annular. And, for example, an engagement window or windows are formed on the retainer holding portion, while an engagement tab or tabs are provided on the main body of the retainer. In such configuration, the retainer is fitted in the retainer holding portion so that the engagement tab or tabs snap-engage in the engagement window or windows. The main body of the retainer, according to U.S. Pat. No. 6,129,393, is formed in C-shape (generally in annular shape) in cross-section to provide sufficient resilient deformability. Thus configured retainer serves for easy fit-in and release operation with respect to a retainer holding portion.
Meanwhile, in a retainer fitting structure wherein a C-shaped retainer or any other retainer having a main body with a space for deformation generally along an entire axial length, long axially, or relatively long axially is adapted, the main body is easily deformed inwardly in the retainer holding portion due to this space for deformation. That is, when external force is exerted on the a main body, especially on an opposite axial side thereof, the main body may be easily deformed inwardly so that the engagement tab or tabs escape out of the engagement window or windows. Then, the retainer rotates with respect to the retainer holding portion. Otherwise, depending on the direction of external force exerted, or if external force is exerted repeatedly, there is a fear that the retainer moves in an inclining direction with respect to an axial direction of the retainer holding portion, and thereby the retainer is released and falls out of the retainer holding portion. In such a case, an operator must fit the retainer in the retainer holding portion correctly and then implement connecting work of a pipe and a connector once again. Therefore, according to need, a rotation preventive means or a retaining means is configured between the retainer and the retainer holding portion to prevent that the retainer rotates in the retainer holding portion or the retainer falls out of a retainer holding portion. As for retainer rotation preventive means or retainer retaining means, an indent formed on one axial end portion of the main body of the retainer and a rotation preventive projection formed on one axial end portion of an inner peripheral surface of the retainer holding portion may be adapted. In this instance, the rotation preventive projection is fitted in the indent. Or, as disclosed in U.S. Pat. No. 5,297,818, a protrusion formed protruding radially outwardly on one axial end portion of a retainer and a recessed portion provided in an inner peripheral surface of a retainer holding portion may be adapted. In this configuration, the protrusion is fitted in the recessed portion.
However, in a retainer fitting structure, for example, as disclosed in U.S. Pat. No. 6,129,393, wherein operation arms are provided on a retainer, an external force is likely to be exerted on an opposite axial end portion of the retainer. A rotation preventive means or retaining means constructed with respect to one axial end portion of the retainer may not function to prevent the retainer from rotating or moving in inclining direction with respect to an axial direction of the retainer holding portion.